植物内生细菌MY1的分离、鉴定及其防治效果

Isolation,Identification and Control Effect of Endophytic Bacteria MY1

为了对植物内生细菌MY1进行分离鉴定,并对其防治效果进行研究,采用组织分离法从多种植株中分离内生细菌,通过平板对峙法筛选具有抑菌效果的菌株MY1,采用生长速率法对MY1菌株代谢物的抑菌活性进行测定,通过菌株形态特征观察、生理生化鉴定以及16S r DNA序列分析,对菌株进行鉴定,利用室内盆栽对其防效进行测定。结果表明,从多株植物中分离到67株内生细菌,其中,从曼陀罗叶片中分离得到内生细菌MY1(为甲基营养型芽孢杆菌(Bacillus methylotrophicus));菌株MY1对供试的14种植物病原真菌均具有良好的抑菌活性,抑菌率均高于76.65%,其中,对谷瘟病菌(Pyricularia grisea)和桃褐腐病菌(Monilinia fructicola)的抑制作用较强,抑菌率分别达到92.65%和98.95%;发酵液经高温处理后抑菌作用明显减弱;MY1发酵液对番茄灰霉病和早疫病均有良好的防治效果,发酵液稀释5~50倍预防和治疗效果均高于60%,其中,发酵液稀释5倍对番茄灰霉病和早疫病的预防和治疗效果较高,防效分别达到86.4%、80.2%和88.9%、82.6%,且与对照试剂腐霉利防效间没有显著差异。试验结果可为生防菌剂的开发奠定基础。

To isolate and identify the plant endophytic bacteria MY1 and study its control effect,the endophytic bacteria from multiple plants was isolated by using tissue isolation method,and the antibacterial strain MY1 was screened by using the plate confrontation method,the antibacterial activity of the metabolites of strain MY1 was determined by using growth rate method.The strain was identified by morphological observation,physiological and biochemical identification and 16 S r DNA sequence analysis,and its control effect was determined by indoor pot culture.The results showed that 67 strains of endophytic bacteria were isolated from multiple plants,among them,the endophytic bacteria MY1(Bacillus methylotrophicus)was isolated from the leaves of Datura(it was Methyltrophic bacillus),which had good antibacterial activity against 14 kinds of plant pathogenic fungi,and the inhibition rate was higher than76.65%.Among them,it had strong inhibition effect on Pyricularia grisea and Monilinia fructicola,with the inhibition rates of 92.65% and 98.95%,respectively.The bacteriostatic effect of fermentation broth was significantly weakened after high temperature treatment.MY1 fermentation broth had good control effect on Botrytis cinerea and Alternaria solani.When MY1 fermentation broth was diluted5-50 times,the preventive and therapeutic effects were higher than 60%,among them,the prevention and therapeutic effect of fermentation broth diluted 5 times on Botrytis cinerea and Alternaria solani was better,with the control effects of 86.4%,80.2%and 88.9%,82.6%,respectively,there was no significant difference with the control effect of procymidone.The results will lay a foundation for the development of biocontrol agents.